Burner and feedstock injection assembly for carbon black reactor

ABSTRACT

A BURNER AND FEEDSTOCK INJECTION ASSEMBLY FOR A CARBON BLACK REACTOR HAVING THREE CONCENTRIC PIPES: A CENTER PIPE FOR FEEDSTOCK; A SECOND PIPE, SURROUNDING THE CENTER PIPES; A THIRD PIPE, SURROUNDING THE SECOND PIPE; AND A PLURALITY (PREFERABLY THREE) OF FUEL-OIL PIPES, DISDOSED WITHIN THE ANNULUS BETWEEN THE SECOND AND THIRD PIPES; THE ENDS OF EACH OF THESE FUEL-OIL PIPES BEING EQUIPPED WITH A SPRAY NOZZLE INCLINDED AT AN ANGLE WITH RESPECT TO THE AXIS OF THE CENTER PIPE. THESE FUEL-OIL PIPES ARE FOR THE INTRODUCTION OF COMBUSTION FUEL INTO THE REACTOR. PREFERABLY, THE ASSEMBLY ALSO INCLUDES A SUBSTANTIALLY CONE-SHAPED FLAMEHOLDER DEVICE MOUNTED CONCENTRICALLY ABOUT THE THIRD PIPE AT THE END THEREOF, SUCH CONE FLARING OUTWARDLY TOWARD THE INTERIOR OF THE REACTOR, SUCH CONE BEING COMPRISED OF A PLURALITY OF VANES OR LOUVERS EACH OF WHICH IS TWISTED AT THE OUTER ENDS THEREOF.

June 13, 1972 B. F. LATHAM. JR., ETAL BURNER AND FEEnsTocx-1NJEcT1oxASSEMBLY FOR CARBON BLACK REACTOR Filed July 31, 1970 IIII INVENTORSWlLLlAM B. CRULL BYBURTON F. LATHAM JR.

4ATTORNEY LP. l y f ,.Illhh ikxuufl i All I:O man United States Patent O3,669,628 BURNER AND FEEDSTOCK INJECTION ASSEM- BLY FOR CARBON BLACKREACTOR Burton F. Latham, Jr., Houston, and William B. Crull,

Dumas, Tex., assignors to Continental Carbon Company, Houston, Tex.

Filed July 31, 1970, Ser. No. 59,961 Int. Cl. C01b 31 00 U.S. Cl.23-259.5 10 Claims ABSTRACT OF THE DISCLOSURE A burner and feedstockinjection assembly for a carbon black reactor having three concentricpipes:

a center pipe for feedstock;

a second pipe, surrounding the center pipe;

a third pipe, surrounding the second pipe;

and a plurality (preferably three) of 'fuel-oil pipes disdosed withinthe annulus between the second and third plpes;

the ends of each of these fuel-oil pipes being equipped with a spraynozzle inclined at an angle with respect to the axis of the center pipe.These fuel-oil pipes are for the introduction of combustion fuel intothe reactor. preferably, the assembly also includes a substantiallycone-shaped iiameholder device mounted concentrically about the thirdpipe at the end thereof, such cone flaring outwardly toward the interiorof the reactor, such cone being comprised of a plurality of vanes orlouvers each of which is twisted at the outer ends thereof.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to the production of carbon black by the injection of a suitablehydrocarbon feedstock into an elongate reactor or combustion chambercontaining high-temperature llames and gases, and more particularly to aburner and feedstock injection assembly for burning a normally liquidhydrocarbon as fuel to provide the heat necessary for the pyrolysis ofthe feedstock to form carbon black. Such assembly also includes meansfor supplying the feedstock to the reactor.

In many instances gas is used as a fuel to the burner; however, insituations where gas is not available, or is not available at aneconomical price, it is desirable to have a burner which is designed forthe use of a normally liquid hydrocarbon fuel. The main object of thisinvention is to provide a burner which will operate satisfactorily on anormally liquid fuel rather than gas.

Description of the prior art Applicants do not claim that oil (ratherthan gas) burners for carbon black reactors are novel per se. Thefollowing patents disclose specific fuel-oil burner injection systemsdesigned for specific carbon black reactors: 3,003,854; 3,060,003;3,290,120; and 3,501,274. U.S. Pat. No. 3,443,761 discloses certain ofthe features of the present invention; however, it can readily be seenthat the assembly of that patent is different and is suitable only foruse with a gaseous fuel.

SUMMARY OF THE INVENTION This invention is a burner and feedstockinjection assembly for an elongate substantially tubular carbon blackreactor comprising:

a center pipe for introduction of feedstock into the reactor, one end ofsaid pipe terminating within the reactor and being equipped with a spraynozzle;

a second pipe, concentrically disposed about the center ICC pipe, oneend of the second pipe terminating approximately ilush with the end ofthe center pipe within the reactor;

a third pipe, concentrically disposed about the second pipe, one end ofthe third pipe terminating within the reactor at a point upstream of theend of the center P1116;

a plurality of fuel-oil pipes disposed within the annulus between thesecond and third pipes and axially parallel to said pipes, said fuel-oilpipes terminating at a point within the reactor downstream of the end ofthe third pipe but upstream of the end of the center pipe, the ends ofsaid fuel-oil pipes being connected with a plurality of spray nozzleseach of which is inclined at an angle of about 15 45 from the axis ofthe center Plpe;

means for. supplying carbon black feedstock to the center pipe;

means for supplying cooling medium to the annulus between the first andsecond pipes;

means for supplying a normally liquid hydrocarbon fuel to the fuel-oilpipes;

means for introducing a stream of process air into said reactor; and

means for directing said stream of process air downstream along theoutside of the third pipe.

Preferably, the assembly also includes a ilameholder or air distributiondevice comprising a substantially coneshaped device mountedconcentrically about the third pipe at the end of said third pipe, saidcone flaring outwardly toward the interior of the reactor at an angle ofabout 5-30 (preferably 10-25) from the vertical, said device beingcomprised of a plurality of vanes or louvers each twisted at the outerend thereof to an angle of about 10-25 Desirably, the assembly alsoincludes means for supplying air to the annulus between the second andthird pipes, together with an annular passageway between the outercircumference of the second pipe and the nozzle ends of the fuel-oilpipes connecting such annulus with the interior portion of the reactor.

BRIEF DESCRIPTION 0F THE DRAWING FIG. l is an elevational view partly insection illustrating the preferred embodiment of the burner andfeedstock injection assembly;

FIG. 2 is a view taken along the line 2--2 of FIG. l;

FIG. 3 is a longitudinal view, partly in section, of one form of asuitable carbon black reactor including the preferred burner andfeedstock injection assembly;

FIG. 4 is a longitudinal view, partly in section, showing anothersuitable form of carbon black reactor including the preferred burner andfeedstock injection assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. l, burner andfeedstock injection assembly 1 will first be described. The feedstockline is center pipe 2 which is slideably mounted within axial pipe 3 andsealed therefrom by means of suitable packing glands included withinclosure member 4. Center pipe 2 is provided with guides (as shown) forproper positioning within axial pipe 3. The downstream end of centerpipe 2 is provided with a suitable spray nozzle 5, which can be anyconventional commercially available nozzle, preferably of the hollowcone type.

The upstream end of axial pipe 3 is provided with a T-connection 6 forintroduction of air into the annulus between the center pipe and theaxial pipe.

The tip of nozzle 5 terminates in approximate ush relationship withaxial pipe 3.

Axial pipe 3 is slideably mounted within the assembly 1 by means ofclosure member 7 equipped with packing glands as shown.

As suggested above, the ow of air through axial pipe tread grades ofblack; whereas, FIG. 4 is designed for the production of carcass grades.

Referring to FIG. 3, preheated air passes through annulus 23 formed byshell 24 and inner tube 25. Portions in order to adjust the properties(particularly modulus and structure) of the carbon black.

Although the specic design of the elongate tubular carbon black ,reactoris not critical to the practice of this invention, we prefer the designshown in FIGS. 3 and 4.

FIG. 3 is particularly suitable for the production of 3 serves to keepthe nozzle 5 from becoming overheated. 5 of the air enter the interiorof the reactor through louvers It is within the scope of this inventionto surround pipe 3 26 in combustion-aid device 27. A portion of thecombuswith a water-cooled jacket so that the burner assembly tion airalso enters the reactor through annular opening can be cooled with waterrather than air. A specific water- 28. The downstream end of the reactorcan be of any suitcooled jacket assembly is disclosed in U.S. patentappliable design as for example FIG. 1 of U.S. Pat. No. 3,256,- cationSer. No. 59,962 tiled July 31, 1970 and now aban- 065 O1 FIG- 1 Of U-S.Pat. NO- 3,256,065-

doned in favor of continuation-in-part application Ser. No. Thepreheated COmbUStOIl ail enters the IeaCtOI' 0f 1.84934fi1ed Sept, 29,1971 FIG. 4 as shown. The downstream end of the reactor of Tubularmember or pipe 8, which is mounted concen- FIG. 4 can be of anyeOllVeDieDt design 3S fel' example trically about the axial pipe 3, ispreferably equipped near FIG. 1 of U.S. Pat.,No. 2,976,127. the upstreamend with expansion joint 9, which in turn is We normally atomize theliquid hydrocarbon fuel outsecured to annular chamber 10. Annularchamber 10 in Side 0f the reactor, Pri0 1' t0 Supplying Such fuel oil t0turn is equipped with pipe 11 for introduction of fuel oil Pipe 11, Withany CODVement ealfylng Huld Sueh aS Steam, in a manner to be describedbelow, air, natural gas, hydrogen or the like. In addition, the fuelrCommunicating with hamber 10 are a plurality (pref. droplets, suspendedin the carrier fluid, are further atomerably three) ef fuel-611 pipes12, one of which is Shown ized at the nozzlein FIG. 1. These fuel-oilpipes v12 are mounted within the EXAMPLES ennuh@ between the axlal'a-rP1Pe 3 and the Surrounding The table below lists typical operatingconditions which j Outer P1Pe 8 of the assembly 1' have beensatisfactorily employed for commercial opera- The downstream ends ofPlpes 12 are Secured to the tions while utilizing the burner andfeedstock injection assembly by means 0f annular member 13- Amulaf mem25 assembly of FIGS. 1 and 2. The normally-liquid fuel used bel 14,Which iS Seel-1red t0 annulal member 13, has a was naphtha of a gravityof about 75 API. The feedstock plurality of holes drilled at an anglethrough said mernwas a highly-aromatic tar from a thermal cracking unitber, one hole for each of the fuel-oil pipes 12. Each hole having agravity of about -1.5 API.

TABLE Run number 1 2 3 4 5 6 7 8 Grade ofearbon black--. HAF HAF-HsHAF-Ls ISAF ISAF-Hs ISAF-Ls SRF FEF Reactor, figure 3 3 3 3 3 4 4Combustion air rate,s.c.f.h. 160,000 150,000 150,000 150,000 180,000180, 000 120,000 150,000 Air preheat temperature, F- 672 550 672 599 394613 625 Naphtha new rate 11), GPH 86. 5 09. 7 72.` 0 00. 7 88 89 76. 772. 5 Axial air rate, s.c.f.h 10,000 10,000 10,000 10, 000 10, 000 10,000 10,000 10,000 Feedstock oil rate, GPH (average) 286 233 267 191 248221 263 266 is equipped with a spray nozzle 15 (preferably a Hat-sprayWhile we have thus described the preferred embodinozzle) inclined at anangle of about 15-45 (preferably 40 ments of the present invention, manyvariations will be 15-25) from the axis of the center pipe. It would besuggested to those skilled in the art. The foregoing descripobvious tothose skilled in the art that annular members tion and examples shouldtherefore not be considered 13 and 14 could be replaced by an annularmember conlimitative; and all such variations and modifications as aretaining an annular groove so that the number of fuel-oil in accord withthe principles described are meant to fall pipes 12 could be less thanthe number of nozzle 15. 4 within the scope of the appended claims.

Preferably, the assembly includes a substantially coneo Having thusdescribed our invention, we claim: shaped device 16 mountedconcentrically about the end 1. In combination with an elongate,substantially tubuof pipe 8, the cone of which flares outwardly towardthe lar carbon black reactor, a burner and feedstock injection interiorof the reactor 22 at an angle of about 530 assembly concentricallydisposed within said reactor at (preferably 10-15) from the vertical,said device being ,l the upstream end thereof, said assembly comprising:comprised of a plurality of vanes or louvers each of which o a centerpipe for introduction of feedstock into the is twisted at the outer endto an angle of about 10-25. reactor, one end of said pipe terminatingwithin the This device 16 functions as a llameholder or airdistribureactor and being equipped with a spray nozzle; tion vane and isadvantageous for at least two reasons: a second pipe, concentricallydisposed about the center (1) it serves to control at least a portion ofthe combustion 55 pipe, one end of the second pipe terminatingapproxiair flowing downstream `along the outer circumference of matelyflush with the end of the center pipe within the pipe 8 by preventingsuch air from blowing the flame to a reactor;

- position too close to axial pipe 3 and the feedstock spray; a thirdpipe, concentrically disposed about the second (2) the twisted vanes orlouvers impart a swirling motion pipe, one end of the third pipeterminating within the to the air, thus helping to disperse the fuelmore evenly 60 reactor at a point upstream of the end of the centerabout the combustion area. pipe;

Desirably, the -assembly also includes an air inlet 18 a substantiallyfrusta-conical device mounted concenand an annular passageway 19 so thata stream of air can trically to the outer circumference of the thirdpipe be swept through annulus 20 and annulus 19 and then to at thedownstream end of said third pipe, said cone the reactor, in order tohelp cool the spray nozzles 15. 6 :daring outwardly from said third pipetoward the FIGS. 3 and 4 show the preferable positioning of burner ointerior of the reactor at an angle of about 5-30 and feedstockinjection assembly 1 in the upstream end of from the vertical, saiddevice being comprised of a an elongate tubular carbon black reactor 22.Preferably, plurality of vanes or louvers each twisted at the theassembly is slideably mounted in the reactor so that the outer endthereof t0 an angle of about 10-25 "g position of the assembly withinthe reactor can be varied a plurality of fuel-oil pipes disposed withinthe annulus between the second and third pipes and axially parallel tosaid pipes, said fuel-oil pipes terminating at a point within thereactor downstream of the end of the third pipe but upstream of the endof the center pipe, the ends of said fuel-oil pipes being connected witha plurality of fuel-spray nozzles each of which is inclined at an angleof about l45 from the axis of the center pipe;

means for supplying carbon black feedstock to the center pipe;

means for supply cooling medium to the annulus between the first andsecond pipes;

means for supplying a normally liquid hydrocarbon fuel to the fuel-oilpipes;

means for introducing a stream of process air into said reactor; and

means for directing said stream of process air downstream along theoutside of the third pipe.

2.. The combination of claim 1 in which the fuel spray nozzles are aatspray nozzles.

3. The combination of claim 1 in which there are three fuel-spraynozzles spaced apart at about 120.

4. The combination of claim 2 in which there are three fuel-spraynozzles spaced apart at about 120.

5. The combination of claim 4 additionally including means for supplyingair to the annulus between the second and third pipes; and an annularpassageway, between the outer circumference of the second pipe and thenozzled ends of the fuel-oil pipes, connecting said annulus with theinterior portion of the reactor.

6. 'I'he combination of claim 1 in which the frustoconical device flaresoutwardly at an angle of about 25 from the vertical and the spraynozzles are inclined at an angle of about -25.

7. The combination of claim 2 in which the frustoconical device aresoutwardly at an angle of about l025 from vertical and the flat-spraynozzles are inclined at an angle of about 15-25.

8. The combination of claim 3 in which the frustoconical device llaresoutwardly at an angle of about 10-25 from the vertical and the Hat-spraynozzles are inclined at an angle of about 15 25.

9. The combination of claim 4 in which the frustoconical device daresoutwardly at an angle of about 10-25 from the vertical and the Hat-spraynozzles are inclined at angle of about 15 25 10. The combination ofclaim 5 in which the frustoconical device ilares outwardly at an angleof about l025 from the vertical and the lHat-spray nozzles are inclinedat an angle of about 1525.

References Cited UNITED STATES PATENTS 3,256,066 6/ 1966 Higgins23-259.S 3,290,120 12/19'66 Wright et al. 23-259.5

JAMES H. TAYMAN, IR., Primary Examiner U.S. Cl. X.R.

